1. Field of the Invention
The application relates to a method utilized in a wireless communication system, and more particularly, to a method of MDT measurement configuration triggering in a wireless communication system.
2. Description of the Prior Art
Coverage is something that a customer can easily notice through the terminal user interface (UI) (i.e. out-of-service area indication), and is a major criteria that a customer considers when comparing service provided by different operators. With the increase in data service provision, downlink throughput is also an important criterion by which many customers judge the performance of the network. Poor uplink coverage will impact user experience in terms of call setup failure/call drop/poor uplink voice quality.
Accordingly, it is very important for operators to be aware of the coverage/throughput their networks provide, and rigorous “drive tests” are performed to collect such information. However, what has to be taken account of is that the drive tests for network optimization purposes is costly and causes also additional CO2 emissions, so it is desirable to develop automated solutions, including involving UEs in the field, in 3GPP to reduce the operator costs for network deployment and operation. Therefore, minimization of drive tests (MDT) functionality involving measurement is performed or logged by UE to collect information in idle mode or connected mode, to reduce network maintenance costs for operators, ensure faster optimization cycle resulting in higher customer satisfaction and nonetheless help to reduce the carbon emission to protect the environment.
Note that, when a UE with MDT functionality receives a MDT measurement configuration message from a network (e.g. Universal Terrestrial Radio Access Network (UTRAN) in Universal Mobile Telecommunications System (UMTS), Evolved Universal Terrestrial Radio Access Network (E-UTRAN) in Long-Term Evolution (LTE), EPC, RNC or core network), the UE shall perform measurement logging for the purpose of MDT.
According to the specification of 3GPP TS 37.320, section 5.1.3, MDT procedure starts at the network side that chooses a public land mobile network (PLMN) with specific UE, a limited region within a PLMN (i.e. limited by a cell list, a TA list, a LA list or a RA list) without specific UE, a PLMN with specific UE, or a limited region within a PLMN with specific UE. However, the applicant notices that if network assign a PLMN without specific UE to do MDT measurement, it wastes wireless network resource and UE battery. In addition, if network assigns a region within a PLMN with/without specific UE, the network will not know issues outside the specific region.